Process of and apparatus for slitting and stretching insole material



March 11, 1952 H. G. LUMBARD 2,588,859 PROCESS OF AND APPARATUS FORSLITTING AND STRETCHING INSOLE MATERIAL Filed June 5, 1947 INVENTOR.

ible for use in insoles.

Patented Mar. 11, 1952 FICE PROCESS OF AND APPARATUS FOR SLIT- TING- ANDSTRETCHING IN SOLE MATERIAL Hen'ry' G. Lumbard, Auburn, MaineApplication June 5, 1947, Serial No. 752,768

2 Claims.

This invention consists in a new and improved process and apparatus ofslitting and stretching fibrous sheet material in order to render itflex- The invention also includes within its scope a novel machine orapparatus whereby the process may be carried out.

One important field for my novel process is in preparing the fibroussheet material which constitutes the forepart of the well-known Lumflexinsole, that is to say, an insole in which the forepart is provided witha series of rows of short, transverse, through-and-through slits whichhave been opened by stretching the slitted stock sufficiently to giveclearance to the opposed edges of the slits in the normal flexing, ofthe insole under the foot of the wearer.

As disclosed in my prior U. S. patent No. 2,181,787 dated November 28,1939, the attempt has been made to slit and stretch the stocksimultaneously by employing beveled edge blades,

but this procedure is not entirely satisfactory in that the stock iscompressed between beveled blades when they are arranged in the desiredcloseproximity and the desired stretching effect is. not alwaysattained. I have found that a more satisfactory and uniform product canbe prepared at a higher rate of speed and under more economicalmanufacturin conditions by first forming rows of short slits in thefibrous strip and subsequently stretching the slitted strip transverselyin longitudinally progressing areas.

Going more into detail, I have found it advantageous from themanufacturing standpoint to slit the fibrous strip by the operation of agang of rotary cutters and then, as the strip is ad vanced by the actionof the cutters and in an area adjacent thereto, temporarily bulging theslitted stock into convex curvature thus progressively stretching thestock and opening the slits.

These and other characteristics of my novel process will be bestunderstood and appreciated from the following description of one form ofmechanism by which it may be carried out, selected for purposes ofillustration and shown in the accompanying drawings in which:

Fig. 1 is a plan view of one form of apparatus which may be used incarrying out the process of my invention,

Fig. 2 is a similar view showing a piece of stock in process.

Fig. 3 is a fragmentary view in longitudinal section on the line 3-3 ofFig. 1,

Fig. 4 is a fragmentary view on an enlarged scale of the cutting andplaten rolls.

Fig. 5 is a detailed view showing one of the cutters in full scale, and

Fig. 6 is a view in perspective of an insole including in its structurethe material produced by the process herein disclosed.

The apparatus herein shown for purposes of illustration will first bedescribed, it being understood that the process is in no sense limitedto the employment of the illustrated apparatus but may be successfullycarried out by any mechanism capable of performing the slitting andstretching steps in the desired sequence. The illustrated apparatuscomprises a frame suppjorting a horizontal work table In at convenientheight. In the frame are provided journals for a driving shaft H havinga roll I2 upon which is mounted a series of uniformly spaced disccutters I 3. The knives are symmetrically beveled to form a sharpenedcircumferential cutting edge, and in the edge of each knifeis provided aseries of notches 14, for example, seven notches approximately in width.The notches interrupt the cutting edge of the disc and in operationleave the material uncut. The disc knives are uniformly spaced bywashers I5 and the whole assembly of knives and washers is clamped inoperative position upon the roll I2, this being belt driven by a pulleyl 6 on the outer end of the drive shaft H.

The drive shaft ll carries gearing I 1 through which a platen shaft [8is positively driven at the same speed as the drive shaft. The platenshaft I8 carries a roll l9 upon which is secured a platen sleeve 20 ofhard fiber or the like. The disc knives l3 and the platen sleeve 20 areso related that the platen sleeve is indented by the knives and anysheet material passed between them is provided with parallel rows ofthroughand-throug'h slits,

Edge gauges 2| are adjustably secure-d to the work table 10 in positionto direct sheet matejrial in a path at right angles to the rolls of themachine. Beyond the rolls hold-down edge gauges 22 and 23 are alsosecured to thework table with provision for suitable adjustment. Thegauges 22 and 23 comprise bars which are undercut or flanged at theiropposite edges so that they have a hold-down function as well as aguiding function.

Midway between the gauges 22 and 23 and spaced a short distance behindthe bite of the rolls, is located a convex pear-shaped stretching member24, this being held permanently in place upon the work table by acountersunk. bolt 25 and a dowel pin 26. The stretching member 24 forexample, from 2 to 6 irons. A strip 21 of such stock, first cut to thedesired width, is represented as being passed between the gauges 2i tothe rolls of the machine. As soon as it reaches the bite of the rolls,the disc knives l3 begin to positively advance it and at the same timeform rows of short through-and-through slits2'l. While still controlledby the rolls and positively advanced by the disc knives, the stockpositively advanced by the action of the notched knives l3, the stock isforced toward and through the stretching zone formed by the stretchingmember 24. In the stretching operation it is bulged upwardly out of itsinitial plane although its side edges are maintained in straight flatposition by the gauges 22 and 23.

The slits 28 leave the gang of rotary knives i3 in substantiallyunstretched condition. Then, as the stock is forced past the stretchingmember and after the knives have been withdrawn from the stock, theslits are opened to their maximum width by transverse tension in thestock. Finally,

- edges.

21, now provided with slits 28, is forced against the pear-shapedstretching member 24 and bulged upwardly over the same. Meanwhile boththe edges of the stock are held down upon the table II] by the hold-downgauges 22 and '23. The effect of the transverse stretching of the stockis to open the slits 28 into elongated diamond-shaped apertures 29.These are opened to their maximum width in passing over the stretchingmember 24, and due to the resiliency of the stock, tend to close to someextent in the stock as it passes beyond the stretching. zone. However,suflicient permanent set is imparted to the stock .so that the oppositeedges of the opened slits Iclear each other in transverse flexing of thestock corresponding to that to which it might be subjected in wear.

The perforated strip as it comes from theslitting and stretchingoperation may now be united .with unslitted strips of the same or aharder .fibermaterial, and from the composite strips thus formed insolesare cut out of the general character illustrated in Fig. 6. In theseinsoles the toe portion 30, together with the shank and heel portion 3|,are formed from the relatively stifi components of. the composite strip,while the forepart 32 which is of course repeatedly flexed in wear isformed from the slitted and stretchedstock .shownin Fig. 2.

' -Asherein shown andas an optional feature,

the forepart of the insole includes a thin cover -ply 33 ofunslittedstock, perhaps 1 -0r 2 irons in thickness.

It will be understood from the foregoing description that the stripstock 21 is presented to the machine in fiat condition upon the worktable It and that it remains in substantially fiat condition while it issubjected to the action of the as the stock passes beyond the stretchingzone, the slits contract somewhat but remain open to an extent thatprovides clearance between their The dashes in the left-end of the stockas shown in Fig. 2 indicate that the partially open slots extend in thatcondition throughout the length of the treated stock.

Having thus disclosed my invention and described in detail anillustrative manner in which it may be put into practice, I claim as newand desire to secure by Letters Patent:

1. The process of rendering flexible a-fibrous strip of insole material,which is characterized by advancing the strip in unheated condition bythe rotation of a series of notched concentric rotary slitting knivesand thus forming longitudinal slits therein, and stretching the slittedstrip transversely in longitudinally progressive areas and opening theslits therein by passing it over a stationary convex former locatedcloselyadjacent to said slitting knives while the stock is to stretchthe slitted stock transversely while the slitting knives l3 and theplaten sleeve 20. Then,

while still under the control of the rolls and strip is forced againstthe stretching member by the action of the rotary cutters, and edgegauges positioned on either side of said stretching member for holdingboth edges of the stock uponthe work table during the stretchingoperation.

. HENRY G. LUMBARD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Date Number Name I 1,510,696 'Naugle et a1. Oct.'7, 1924 2,181,787 Lumbard Nov. 28, 1939 2,294,478 Norris et a1.Sept..1, 1942

